Post Modification Research Articles

Triazination/IEDDA Cascade Modular Strategy Installing Pyridines/Pyrimidines onto Tyrosine Enables Peptide Screening and Optimization.

Modular chemical postmodification of peptides is a promising strategy that supports the optimization and innovation of hit peptide therapeutics by enabling rapid derivatization. However, current methods are primarily limited to traditional bio-orthogonal strategies and chemical ligation techniques, which require the preintroduction of non-natural amino acids and impose fixed methods that limit peptide diversity. Here, we developed the Tyrosine-1,2,3-Triazine Ligation (YTL) strategy, which constructs novel linkages (pyridine and pyrimidine) through a "one-pot, two-step" process combining SNAr and IEDDA reactions, promoting modular post modification of Tyr-containing peptides. After optimizing the YTL strategy and establishing standard procedures, we successfully applied it to the solid-phase postmodification of various biorelated peptides, such as the synthesis of dual-mode imaging probes and long-acting GLP-1 analogs. As a proof of concept, a library of 384 amphipathic peptides was constructed using YTL based on 96-well microfiltration plates. Modular modifications were then performed on the screened template tripeptide RYR, leading to the generation of 20 derivatives. The antibacterial activity of these derivatives was systematically characterized, identifying Z8 as a potential antibacterial candidate.

Multipurpose adsorption applications of boron-doped and amino-functionalized magnetic mesoporous silica nanocomposite.

In this study, boron-doped magnetic mesoporous silica nanocomposite was prepared through the hydrothermal synthesis procedure followed by post modification with -NH2 groups. The higher surface area, more ordered mesoporous structure, and higher surface charge density obtained by boron doping and amino functionalization contributed to the use of nanocomposite for multipurpose application functions. When used as an adsorbent for light green (LG) anionic dye, boron-doped nanocomposite exhibited higher adsorption capacity (105.80mg/g) compared to undoped nanocomposite (72.23mg/g), while when used as a drug carrier for Doxorubicin (DOX), a sufficient drug loading capacity (48.0mg/g) was obtained, which is also higher than that of undoped nanocomposite (30.3mg/g). In terms of LG adsorption, the effects such as initial concentration, adsorbent dosage, time, pH, and temperature on the adsorption properties were investigated in detail. Adsorption kinetics, isotherms, thermodynamics, and reusability are discussed. The existence of small quantity of boron doping enhanced the surface charge density from 0.0393 to 0.2854 C/m2, which resulted in higher adsorption capacity for LG adsorption dominated by electrostatic attraction, and led to formation of silanol holes together with the -OH and -NH2 functional groups, which resulted in higher drug loading capacity for DOX adsorption dominated by hydrogen bonding. This promising result provides that boron-doped and -NH2 grafted magnetic mesoporous silica material can function as multipurpose adsorbent for various environmental applications.

Copper‐Catalyzed Tandem Cyclization of 2‐(Alkynylaryl)Acetonitriles and Amines: Access to 3‐Hydroxyisoindolinones

AbstractHerein, we describe an approach to the synthesis of 3‐hydroxyisoindolinone derivatives via copper‐catalyzed tandem cyclization of 2‐(alkynylaryl)acetonitriles and amines. This reaction is compatible with 2‐(alkynylaryl)acetonitriles and primary alkyl amines containing various functional groups, providing the corresponding 3‐hydroxyindolinone derivatives with yields ranging from 44%–82%. Preliminary mechanistic studies suggest that the reaction involves oxidation of the benzylic carbon, amide formation, hydration of the alkyne and intramolecular cyclization to produce various 3‐hydroxyisoindolinones. The practicality of the strategy was further demonstrated by gram‐scale synthesis, late‐stage functionalizations, and the post modification of natural products.

Mechanically robust MOF beads for efficient ethylene/ethane separation with fast adsorption kinetics

Shaping of metal-organic frameworks (MOFs) without obvious mass transfer resistance is crucial for scaled-up adsorption separation process. Herein, mechanically robust ultramicroporous MOF (ZU-901, also termed CPL-1-CH3) beads with hierarchical porosity were structured through the calcium alginate (CA) method, which preserved the adsorption separation performance and demonstrated fast gas diffusion rates. The highly crosslinked networks of CA contributed to the excellent mechanical properties of 95 % ZU-901@CA beads with Young’s modulus up to 1.81 MPa and a low abrasion rate of 0.32 %, superior to that of 95 % ZU-901@HPC extrudates (1.13 %). Compared with powder of ZU-901, the C2H4 capacity of ZU-901@CA beads showed only 3 % loss at 298 K. The C2H4 diffusion time constant of 95 % ZU-901@CA beads (7.06 × 10−3 s−1) was comparable to that of the powders (7.61 × 10−3 s−1) and higher than that of ZU-901@HPC extrudates (2.95 × 10−3 s−1). Breakthrough experiments confirmed that ZU-901@CA beads performed well in the dynamic separation of C2H4/C2H6 binary mixture, and could be easily regenerated at room temperature. In addition, after post modification on the exterior of ZU-901 beads, the water contact angle increased from 0° to 119°. Therefore, the mechanically robust ZU-901@CA beads showed great potential in energy-efficient C2H4/C2H6 separation.

Role of artificial intelligence in staging and assessing of treatment response in MASH patients.

The risk of disease progression in MASH increases proportionally to the pathological stage of fibrosis. This latter is evaluated through a semi-quantitative process, which has limited sensitivity in reflecting changes in disease or response to treatment. This study aims to test the clinical impact of Artificial Intelligence (AI) in characterizing liver fibrosis in MASH patients. The study included 60 patients with clinical pathological diagnosis of MASH. Among these, 17 received a medical treatment and underwent a post-treatment biopsy. For each biopsy (n = 77) a Sirius Red digital slide (SR-WSI) was obtained. AI extracts >30 features from SR-WSI, including estimated collagen area (ECA) and entropy of collagen (EnC). AI highlighted that different histopathological stages are associated with progressive and significant increase of ECA (F2: 2.6% ± 0.4; F3: 5.7% ± 0.4; F4: 10.9% ± 0.8; p: 0.0001) and EnC (F2: 0.96 ± 0.05; F3: 1.24 ± 0.06; F4: 1.80 ± 0.11, p: 0.0001); disclosed the heterogeneity of fibrosis among pathological homogenous cases; revealed post treatment fibrosis modification in 76% of the cases (vs 56% detected by histopathology). AI characterizes the fibrosis process by its true, continuous, and non-categorical nature, thus allowing for better identification of the response to anti-MASH treatment.

Photoinduced Decarboxylative Thioacylation of N-Hydroxyphthalimide Esters with Tetraalkylthiuram Disulfides.

Dithiocarbamate is a key structural sequence in pharmaceuticals and agrochemicals, and its synthesis is crucial in organic chemistry. Although significant progress has been made in related synthesis research, developing a practical and universal synthesis method remains fascinating. Herein, we report a new visible-light-induced decarboxylation coupling reaction between N-hydroxyphthalimide esters and tetraalkylthiuram disulfides, which uses Ir(ppy)3 as a photocatalyst to promote the generation of corresponding decarboxylation thioacylation product-dithiocarbamates in high yields. This redox-neutral protocol uses inexpensive and readily available starting material under mild reaction conditions, exhibiting broad substrate scope and wide functional group compatibility. This method can be further used for post modification of complex natural products and bioactive drugs.

Chiral-induced covalent organic framework as novel chiral stationary phase for chiral separation using open-tubular capillary electrochromatography

As a novel class of chiral stationary phase (CPS) material, chiral covalent organic frameworks (CCOFs) have already shown great promise in open-tubular capillary electrochromatography (OT-CEC) for chiral separation. The synthesis methods of CCOFs used in OT-CEC mainly include bottom-up, post modification and chiral induction. The CCOFs synthesized by bottom-up and post modification strategies already have lots of applications in capillary electrochromatography, however, the chiral-induced synthesized via an asymmetric catalytic strategy has not yet been reported for using as the chiral stationary phase (CPS) in OT-CEC or even in chromatographic separation. Herein, the chiral-induced COF (Λ)-TpPa-1 was synthesized by asymmetric catalytic synthesis and coated on the inner surface of a capillary by an in-situ growth strategy as the CPS for chiral drug separation. The baseline separation of six enantiomers was achieved within 14 min, with a high-resolution (Rs) range from 1.85 to 6.75. Moreover, the resolution and migration time of the capillary keep stable within 160 runs, showing its superior stability and repeatability. This research provides a new idea for the development and application of novel CPS materials in the field of capillary electrochromatography separation, also shows the new application of chiral induced COFs. Furthermore, the chiral-induced CCOFs can be easily applied to other chromatographic separation fields, exhibiting its extensive application value in chiral analysis separation.

General In Situ Engineering of Carbon-Based Materials on Carbon Fiber for In Vivo Neurochemical Sensing.

Developing real-time, dynamic, and in situ analytical methods with high spatial and temporal resolutions is crucial for exploring biochemical processes in the brain. Although in vivo electrochemical methods based on carbon fiber (CF) microelectrodes are effective in monitoring neurochemical dynamics during physiological and pathological processes, complex post modification hinders large-scale productions and widespread neuroscience applications. Herein, we develop a general strategy for the in situ engineering of carbon-based materials to mass-produce functional CFs by introducing polydopamine to anchor zeolitic imidazolate frameworks as precursors, followed by one-step pyrolysis. This strategy demonstrates exceptional universality and design flexibility, overcoming complex post-modification procedures and avoiding the delamination of the modification layer. This simplifies the fabrication and integration of functional CF-based microelectrodes. Moreover, we design highly stable and selective H+, O2, and ascorbate microsensors and monitor the influence of CO2 exposure on the O2 content of the cerebral tissue during physiological and ischemia-reperfusion pathological processes.

Leveraging an innovative process integration using highly acid-immune blend membranes for enhanced acid recovery and selective salt separation

We investigate the efficiency and advantage of the integrated diffusion dialysis-electrodialysis (DD-ED) system over the DD process for acid recovery with highly acidic wastewater. The investigation uses various acid (HCl/H2SO4) /salt mixtures encompassing iron, copper and aluminium salts (FeCl2, CuCl2, AlCl3, and FeSO4) as simulated feed. The membrane is prepared using blend mixture of polyvinylidene fluoride (PVDF) and polymethyl methacrylate-co-poly chloromethyl styrene copolymer (PMMA-co-PCMSt) solution by non-solvent induced phase inversion on a nonwoven fabric followed by treatment with different tertiary amines. Representative AEM-Q3 membrane prepared by the post modification of blend membrane with a mixture of N, N, N’, N’- tetramethyl diamino hexane (TMDAH) and trimethyl amine (TMA) (1: 1 w/w %) exhibited the best-balanced performance. The membrane recovered a 84.2% AR (%) of acid with 96.28% purity (%) at a flux (JH+) of 7.08 × 10-4 mol cm-2 h-1 from 3 M HCl and 0.2M FeCl2 mixture making it suitable for further studies. A comprehensive comparative study drawn between the DD and integrated DD-ED showed that there was a 2.3 fold increment in acid recovery for the integrated process over the DD process (for the HCl-FeCl2 system). The membranes have also shown good monovalent (Cl-) and bivalent (SO42-) anion selectivity of 7.8. However, the selectivity was further improved to 12.28 by modification of AEM-Q3 membrane, which is double side cast (referred as AEM-Q3/b). The synthetic strategy of the membrane is easy and scalable and has potential for both acid recovery and selective salt separation by ED process.

General In Situ Engineering of Carbon‐Based Materials on Carbon Fiber for In Vivo Neurochemical Sensing

AbstractDeveloping real‐time, dynamic, and in situ analytical methods with high spatial and temporal resolutions is crucial for exploring biochemical processes in the brain. Although in vivo electrochemical methods based on carbon fiber (CF) microelectrodes are effective in monitoring neurochemical dynamics during physiological and pathological processes, complex post modification hinders large‐scale productions and widespread neuroscience applications. Herein, we develop a general strategy for the in situ engineering of carbon‐based materials to mass‐produce functional CFs by introducing polydopamine to anchor zeolitic imidazolate frameworks as precursors, followed by one‐step pyrolysis. This strategy demonstrates exceptional universality and design flexibility, overcoming complex post‐modification procedures and avoiding the delamination of the modification layer. This simplifies the fabrication and integration of functional CF‐based microelectrodes. Moreover, we design highly stable and selective H+, O2, and ascorbate microsensors and monitor the influence of CO2 exposure on the O2 content of the cerebral tissue during physiological and ischemia‐reperfusion pathological processes.

Preparation and chromatographic evaluation of hydrophilic polymer brushes grafted-silica with post modification of silicon/carbon dots as a green liquid chromatography stationary phase.

Polar stationary phases were prepared by grafting hydrophilic acrylamide (Am) polymer brushes with post modification of carbon dots (CDs) and silicon dots (SiDs) onto SiO2 particles. The prepared stationary phases, SiO2-PAm-CDs, SiO2-PAm-CDs/SiDs, and SiO2-PAm-SiDs, were packed as chromatographic columns, respectively. Using nucleic bases, organic acids, and β-agonists as targetsubstances to investigate the influence of chromatographic conditions on retentionand separation, the packed columns showed the partitioning and adsorption of mixed retention behavior in hydrophilic interaction liquid chromatography mode and successfully separated thepolar compounds. Most importantly, under per aqueous liquid chromatography mode (using 100% water as mobile phase), those columns still had goodseparation ability toward nucleic bases, β-agonist, and organic acids. Because AM isa temperature-sensitive monomer, the resulting van't Hoff curves exhibited a nonlinear relationship, having temperature-responsive chromatographic characteristic under pure water separation. Hence, building on temperature-sensitive characteristics and pure water of separation conditions, the separation selectivity toward hydrophilic compounds greatly improved. Compared with the commercial hydrophilic columns, the efficiency of our developed column had the superior ability in separation and detection of betaine in Goji berry with the enhanced resolution achieved in the proposedgreen separation method(just using pure water as mobile phase).

Effect of SIRT6 Silencing On Post-Translational Modification of AKT Signalling Pathway in Non-Small Cell Lung Cancer Cell Lines

SIRT6 has been suggested that SIRT6 functions in cells as a helpful modulator and tumor suppressor. Because the induction or blocking of apoptosis affects the course of cancer, SIRT6 has a dual function in the growth and spread of tumors. This study aims to investigate the post transilational modification at AKT signaling pathway under SIRT6 slicening. The main objectives are Silencing SIRT6 by siRNA (SIRT6 siRNA 1, SIRT6 siRNA 2), Investigation of the phosphorylation status of AKT, Examining PTEN expression and examining the AKT pathway while SIRT6 is silenced. To evaluate the SIRT6, phospho-AKT, AKT, and PTEN proteins, western blot was used. It was discovered that SIRT6 expression was significantly elevated in both NSCLC cells and primary lung cancers. Mechanistic research has shown that silencing SIRT6 increases AKT phosphorylation. Overall, the research demonstrated that SIRT6 downregulation induced posttranslational modification in NSCLC cell lines to control AKT/Wnt/β-catenin signaling, offering a potential biomarker and strategy for lung cancer prevention.

Temperature self-compensated fiber-optic Pb(II) sensor with improved selectivity by Resorcylaldehyde post-modified organic metal framework

Post-modification of metal-organic framework (MOF) materials is an effective means to enhance their efficient and selective adsorption for heavy metal ions. In this article, we presented a reflection-type optical fiber surface plasmon resonance (SPR) sensor based on dual core fiber (DCF) coated with UiO-66-RSA (UiO-66-NH2 post-modified with resorcinol aldehyde) film for the specific detection of Pb(II) in aqueous media. The composite material UiO-66-RSA exhibits stronger affinity and specificity for Pb(II) than UiO-66-NH2. The adsorption of Pb(II) can change the equivalent refractive index (RI) of UiO-66-RSA film, causing a regular shift in SPR spectra. Experiments have shown that the limit of detection (LOD) of the SPR Pb(II) sensor can reach 0.1 nM. Meanwhile, research has found that the SPR sensor is accompanied by temperature crosstalk of 0.356 nm/°C. Therefore, we constructed a Michelson temperature interferometer using polymer micro tips on the end face of the fiber core to achieve temperature compensation. Based on the above two sensing channels, dual parameter demodulation of Pb(II) concentration and temperature can be achieved with an error rate of less than 0.5 %. This article has potential research value in exploring the application of post modification techniques of MOF in fiber optic lead ion detection.

Lanthanide doped metal−organic framework: novel turn-on fluorescent sensing of iodide in kelp and seawater samples

An effective fluorescence sensor was developed for iodide detection, with copper-based metal−organic frameworks (Cu-BTC) into which Tb3+ was doped by post modification. Tb@Cu-BTC manifested the characteristic emission of Tb3+ resulted from efficient sensitization through antenna effect, which was further exploited as a “turn-on” fluorescence probe to determinate iodide in aqueous solution. The sensor exhibited two great linear ranges of 12.5 ∼ 40 μM and 40 ∼ 160 μM, with a good limit of detection of 4.7 μM for iodide. These results showed that Tb@Cu-BTC exhibited high selectivity, excellent stability and great anti-interference capability for iodide monitoring. The possible mechanism could be object-induced luminescence. In addition, recovery experiments have been carried out to determine iodide in tap water and sea water. This method based on Tb@Cu-BTC could also be potentially employed to determinate iodide in other samples.

Spectroscopic investigations of a commercial graphite screen printed electrode modified by bismuth oxide drop deposition and electrochemical reduction, for cadmium and lead ions simultaneous determination

A single use graphite screen-printed electrode (GSPE) was easily modified, to take advantage of the proven affinity of the nontoxic post-transition metal bismuth (Bi), for metal ions to be detected by Square Wave Anodic Stripping Voltammetry (SWASV). A bismuth oxide (Bi2O3) or a chitosan coated (CS@Bi2O3) nanopowder suspension was drop-casted on the graphite working electrode (WE) surface, giving rise to the precursor of a Bi-modified GSPE. After that, an electrochemical reduction was performed to obtain the Bi– or the CS@Bi–GSPE.X-ray photoelectron spectroscopy and micro-X-ray fluorescence investigations were performed on the graphitic structure pre and post modification. The bismuth oxide deposition amount was considered as critical parameter to sensor performance, indicating a minimum and maximum threshold. Under improved measurement conditions, with a 300 s pre-concentration time, the attained sensors exhibited a linearity in the range (2.0–20.0) μg L−1 in the simultaneous analysis of Pb(II) and Cd(II). The Bi–GSPE showed LODs of 1.7 and 0.5 μg L−1 for Cd(II) and Pb(II) respectively, while 1.5 μg L−1 for Cd(II) and 0.2 μg L−1 for Pb(II) were recorded by the CS@Bi–GSPE. As an applicative proof in real sample, a spike test was carried out in a ground water sample, without any preliminary sample treatment.

PEG-functionalized aliphatic polycarbonate brushes with self-polishing dynamic antifouling properties

Hydrophilic antifouling polymers provide excellent antifouling effects under usual short-term use conditions, but the long-term accumulation of contaminants causes them to lose their antifouling properties. To overcome this drawback, surface-initiated ring-opening graft polymerization (SI-ROP) was performed on the surface of the material by applying the cyclic carbide monomer 4′-(fluorosulfonyl)benzyl-5-methyl-2-oxo-1,3-dioxane-5-carboxylate (FMC), which contains a sulfonylfluoride group on the side chain, followed by a “sulfur(IV)-fluorine exchange” (SuFEx) post click modification reaction to link the hydrophilic polyethylene glycol (PEG) to the polyFMC (PFMC) brush, and a novel antifouling strategy for self-polishing dynamic antifouling surfaces was developed. The experimental results showed that the antifouling surface could effectively prevent the adsorption of proteins such as bovine serum albumin (BSA, ∼96.4%), fibrinogen (Fg, ∼87.8%) and lysozyme (Lyz ∼69.4%) as well as the adhesion of microorganisms such as the bacteria Staphylococcus aureus (S. aureus) (∼87.5%) and HeLa cells (∼67.2%). Moreover, the enzymatically self-polished surface still has excellent antifouling properties. Therefore, this modification method has potential applications in the field of biosensors and novel antifouling materials.

Physicochemical Properties of Inorganic and Hybrid Hydroxyapatite-Based Granules Modified with Citric Acid or Polyethylene Glycol.

This study delves into the physicochemical properties of inorganic hydroxyapatite (HAp) and hybrid hydroxyapatite-chitosan (HAp-CTS) granules, also gold-enriched, which can be used as aggregates in biomicroconcrete-type materials. The impact of granules' surface modifications with citric acid (CA) or polyethylene glycol (PEG) was assessed. Citric acid modification induced increased specific surface area and porosity in inorganic granules, contrasting with reduced parameters in hybrid granules. PEG modification resulted in a slight increase in specific surface area for inorganic granules and a substantial rise for hybrid granules with gold nanoparticles. Varied effects on open porosity were observed based on granule type. Microstructural analysis revealed increased roughness for inorganic granules post CA modification, while hybrid granules exhibited smoother surfaces. Novel biomicroconcretes, based on α-tricalcium phosphate (α-TCP) calcium phosphate cement and developed granules as aggregates within, were evaluated for compressive strength. Compressive strength assessments showcased significant enhancement with PEG modification, emphasizing its positive impact. Citric acid modification demonstrated variable effects, depending on granule composition. The incorporation of gold nanoparticles further enriched the multifaceted approach to enhancing calcium phosphate-based biomaterials for potential biomedical applications. This study demonstrates the pivotal role of surface modifications in tailoring the physicochemical properties of granules, paving the way for advanced biomicroconcretes with improved compressive strength for diverse biomedical applications.

Modification of amino functionalized silica nanoparticles with L-proline and furanacrylic acid as novel composites for the efficient removal of methyl orange

The present study deals with the preparation of new composites in which L-proline (LP) and furnacrylic acid (FA) have been grafted on surface of amino functionalized silica nanoparticles (AFS). At first, AFS were prepared by sol-gel approach using tetraethoxysilane (TEOS) as silica source and aminopropyltriethoxysilane (APTES) as silica modifiers. Taking the advantage of amino group on AFS surface, LP and FA were easily grafted on silica surface to obtain LP grafted silica (AFS-LP) and FA grafted silica (AFS-FA) nanocomposites by post modification approach. As prepared composites were characterized by FTIR, SEM, XRD and TGA. The evidence of LP and FA on AFS was elucidated from the FTIR bands found at 1650–1698 cm−1 related to carbonyl group CO) of amide. Additionally, peaks observed at 2965 cm−1 (C-H stretching) of propyl groups and at 1050 cm−1 (Si-O-Si) indicated that the backbone of the material is preserved as silica. The micro images of SEM depicted that the AFS are spherical in shape and have more degree of monodispersivity whereas the SEM images of composites (AFS-LP and AFS-FA) have larger particle size and less degree of monodispersivity. Likewise, XRD peaks at 2θ (∼12°) revealed the mesoporosity of silica as well as hybrid silica and further depression in this peak in case of AFS-LP and AFS-FA depicted the existence of organic moieties on silica. TGA analysis depicted three decomposition steps (high weight loss) in case of AFS-LP and AFS-FA in contrast to two decomposition steps observed in case of AFS. The higher weight loss observed in the case of hybrid composites depicted the grafting of organic molecules on AFS. The prepared composites AFS-LP and AFS-FA were deployed to investigate their adsorption capacity to remove methyl orange (MO) from aqueous media. Experiments revealed that the composites have high adsorption capacity in acidic media (pH=2) with % removal of 85.05 % for AFS-LP and 81.70 % for AFS-FA. The experimental data was evaluated for adsorption isotherms and value of correlation factor (R2) was close to unity in case of Freundlich representing that the adsorption follows Freundlich isotherm. The data was also evaluated for kinetic models and higher values of R2 as well as closeness of experimental and calculated values of Qe predicted that adsorption of MO followed pseudo-second order kinetic model.

In situ conversion of ZnO anchored on porous carbon foams to antiflexible ZIF-8-X (X = Co or NH2) for sieving linear and mono-branched hexane isomers

Efficient separation of linear hexane from their isomers is a vital petrochemical process to produce high-quality gasoline. Zeolitic imidazolate frameworks-8 (ZIF-8), one of the most famous metal-organic frameworks (MOFs), is a promising separation material due to its special pore size (3.4 Å), whereas the flexible framework limited its separation ability, showing unsatisfied trade-off between adsorption capacity and separation selectivity. Here, we propose a novel strategy of post metal-oxide modification (PMOM) to suppress ZIF-8 flexibility by in situ growth on rigid layer of porous carbon foam (PCF) based the intermediation of anchored ZnO nanoparticles directly obtained from the pyrolysis of sucrose and zinc nitrate mixture. Afterwards, synergistic flexible suppression technology (SFST) was adopted to design antiflexible PCF/ZIFs with mixed-metal and mixed-ligand, including bi-metal PCF/ZIF-8-Co and di-ligand PCF/ZIF-8-NH2. Therein, the tight interfaces generated with benzene-ring inhabited the swinging of linkers and hindered 3-MP entry into the pore channels, showing both remarkable nHex adsorption capacity (q = 2.26 mmol·g−1) and nHex/3-MP selectivity (Su = 9.42). Moreover, bi-component adsorption experiments confirm the practical separation performance and cycling stability, showing promising application in adsorptive separation processes.

Rational design of covalent organic frameworks/NaTaO3 S-scheme heterostructure for enhanced photocatalytic hydrogen evolution

As a typical perovskite material, NaTaO3 has been regarded as a potential catalyst for photocatalytic hydrogen evolution (PHE) process, due to its excellent photoelectric property and superior chemical stability. However, the photocatalytic activity of pure NaTaO3 was largely restricted by its poor visible-light absorption ability and rapid recombination of photogenerated charge carriers. Therefore, a covalently bonded TpBpy covalent organic framework (COF)/NaTaO3 (TpBpy/NaTaO3) heterostructure was designed and synthesized by the post modification strategy with (3-aminopropyl) triethoxysilane (APTES) and the in situ solvothermal process. Benefiting from the enhanced built-in electric field by the interfacial covalent bonds and the formation of S-scheme heterostructure between TpBpy and NaTaO3, which were proved by the Ar+-cluster depth profile and X-ray photoelectron spectroscopy (XPS), as well as density functional theory (DFT) calculation results, both the charge transfer efficiency and the PHE performance of the TpBpy/NaTaO3 composites were significantly improved. Additionally, the composites exhibited an excellent absorption performance in the visible region, which was also beneficial for the photocatalytic process. As expected, the optimal TpBpy/20%NaTaO3 composite achieved a remarkable hydrogen evolution rate of 17.3 mmol·g−1·h−1 (10 mg of catalyst) under simulated sunlight irradiation, which was about 173 and 2.4 times higher than that of pure NaTaO3 and TpBpy, respectively. This work provided a novel strategy for constructing highly effective and stable semiconductor/COFs heterostructures with strong interfacial interaction for photocatalytic hydrogen evolution.